Beste F. Yuksel

Using fNIRS brain sensing to evaluate information visualization interfaces

We show how brain sensing can lend insight to the evaluation of visual interfaces and establish a role for fNIRS in visualization. Research suggests that the evaluation of visual design benefits by going beyond performance measures or questionnaires to measurements of the users cognitive state. Unfortunately, objectively and unobtrusively monitoring the brain is difficult. While functional near-infrared spectroscopy (fNIRS) has emerged as a practical brain sensing technology in HCI, visual tasks often rely on the brains quick, massively parallel visual system, which may be inaccessible to this measurement. It is unknown whether fNIRS can distinguish differences in cognitive state that derive from visual design alone. In this paper, we use the classic comparison of bar graphs and pie charts to test the viability of fNIRS for measuring the impact of a visual design on the brain. Our results demonstrate that we can indeed measure this impact, and furthermore measurements indicate that there are not universal differences in bar graphs and pie charts.

A novel brain-computer interface using a multi-touch surface

We present a novel integration of a brain-computer interface (BCI) with a multi-touch surface. BCIs based on the P300 paradigm often use a visual stimulus of a flashing character to elicit an event related potential in the brains EEG signal. Traditionally, P300-based BCI paradigms use a grid layout of visual targets, commonly an alphabet, and allow users to select targets using their thoughts. In our new system a multi-touch table senses objects placed upon its surface and the system can highlight the objects on the table by flashing an area of light around them. This allows us to construct a P300-based BCI that uses a user-assembled collection of objects as targets, rather than a pre-determined grid layout. An experiment shows that our new paradigm works just as well as the traditional paradigms, thus highlighting the potential for BCIs to be integrated in a broader range of situations.

Using fNIRS to Measure Mental Workload in the Real World

In the past decade, functional near-infrared spectroscopy (fNIRS) has seen increasing use as a non-invasive brain sensing technology. Using optical signals to approximate blood-oxygenation levels in localized regions of the brain, the appeal of the fNIRS signal is that it is relatively robust to movement artifacts and comparable to fMRI measures. We provide an overview of research that builds towards the use of fNIRS to monitor user workload in real world environments, and eventually to act as input to biocybernetic systems. While there are still challenges for the use of fNIRS in real world environments, its unique characteristics make it an appealing alternative for monitoring the cognitive processes of a user.

Brain-based target expansion

The bubble cursor is a promising cursor expansion technique, improving a users movement time and accuracy in pointing tasks. We introduce a brain-based target expansion system, which improves the efficacy of bubble cursor by increasing the expansion of high importance targets at the optimal time based on brain measurements correlated to a particular type of multitasking. We demonstrate through controlled experiments that brain-based target expansion can deliver a graded and continuous level of assistance to a user according to their cognitive state, thereby improving task and speed-accuracy metrics, even without explicit visual changes to the system. Such an adaptation is ideal for use in complex systems to steer users toward higher priority goals during times of increased demand.

Brain-Computer Interfaces for Artistic Expression

Artists have been using BCIs for artistic expression since the 1960s. Their interest and creativity is now increasing because of the availability of affordable BCI devices and software that does not require them to invest extensive time in getting the BCI to work or tuning it to their application. Designers of artistic BCIs are often ahead of more traditional BCI researchers in ideas on using BCIs in multimodal and multiparty contexts, where multiple users are involved, and where robustness and efficiency are not the main matters of concern. The aim of this workshop is to look at current (research) activities in BCIs for artistic expression and to identify research areas that are of interest for both BCI and HCI researchers as well as artists/designers of BCI applications.

Brains or Beauty: How to Engender Trust in User-Agent Interactions

Software-based agents are becoming increasingly ubiquitous and automated. However, current technology and algorithms are still fallible, which considerably affects users’ trust and interaction with such agents. In this article, we investigate two factors that can engender user trust in agents: reliability and attractiveness of agents. We show that agent reliability is not more important than agent attractiveness. Subjective user ratings of agent trust and perceived accuracy suggest that attractiveness may be even more important than reliability.

Building implicit interfaces for wearable computers with physiological inputs: zero shutter camera and phylter

We propose implicit interfaces that use passive physiological input as additional communication channels between wearable devices and wearers. A defining characteristic of physiological input is that it is implicit and continuous, distinguishing it from conventional event-driven action on a keyboard, for example, which is explicit and discrete. By considering the fundamental differences between the two types of inputs, we introduce a core framework to support building implicit interface, such that the framework follows the three key principles: Subscription, Accumulation, and Interpretation of implicit inputs. Unlike a conventional event driven system, our framework subscribes to continuous streams of input data, accumulates the data in a buffer, and subsequently attempts to recognize patterns in the accumulated data -- upon request from the application, rather than directly in response to the input events. Finally, in order to embody the impacts of implicit interfaces in the real world, we introduce two prototype applications for Google Glass, Zero Shutter Camera triggering a camera snapshot and Phylter filtering notifications the both leverage the wearers physiological state information.

Using Animation to Alleviate Overdraw in Multiclass Scatterplot Matrices

The scatterplot matrix (SPLOM) is a commonly used technique for visualizing multiclass multivariate data. However, multiclass SPLOMs have issues with overdraw (overlapping points), and most existing techniques for alleviating overdraw focus on individual scatterplots with a single class. This paper explores whether animation using flickering points is an effective way to alleviate overdraw in these multiclass SPLOMs. In a user study with 69 participants, we found that users not only performed better at identifying dense regions using animated SPLOMs, but also found them easier to interpret and preferred them to static SPLOMs. These results open up new directions for future work on alleviating overdraw for multiclass SPLOMs, and provide insights for applying animation to alleviate overdraw in other settings.